A light source unit (10-1) includes a light source unit having a semiconductor laser (18-1) for emitting primary light, and a connector (14) of a connection portion (22) provided on an optical path of the primary light and to and from which an optical conversion unit is attachable and removable, the optical conversion unit including an optical conversion element for converting optical properties of the primary light to generate secondary light. The light source unit further includes an optical conversion unit group including a plurality of optical conversion units (12-1, 12-2, 12-3). The optical conversion units (12-1, 12-2, 12-3) belonging to the optical conversion unit group are connectible to the light source unit by the connection portion. Hence, when the connection is made using the compatible connection portion (22) which allows a corresponding one of the optical conversion units (12-1, 12-2, 12-3) to be combined with the light source unit (10-1), various types of illumination light can be implemented using a small number of members.
